In this paper, the similarity solution of turbulent boundary layer flow on the flat plate with zero pressure gradients is presented. By employing similarity variables the governing partial differential equations are transformed to ordinary ones with inconsistent coefficients and solved numerically with the use of Runge–Kutta and shooting methods in conjunction with trial and error procedure. Fo...

We present large-eddy simulations (LES) of separation and reattachment of a flat-plate turbulent boundary-layer flow. Instead of resolving the near wall region, we develop a two-dimensional virtual wall model which can calculate the timeand space-dependent skin-friction vector field at the wall, at the resolved scale. By combining the virtual-wall model with the stretched-vortex subgrid-scale (...

The contribution deals with recent theoretical results concerning separation of a turbulent boundary layer from a blunt solid object in a uniform stream, accompanied by a numerical study. The investigation is restricted to incompressible nominally steady two-dimensional flow past an impervious obstacle surface. Then the global Reynolds number represents the only parameter entering the descripti...

An experimental investigation was conducted to quantify the characteristics of the turbulent boundary layer flows over a dimpled surface in comparison to those over a conventional flat plate. In addition to measuring surface pressure distributions to determine the friction factors of the test plates and to map the surface pressure inside the dimple cavity, a high-resolution digital particle ima...

Reynolds-averaged Navier–Stokes (RANS) methods often cannot predict shock/turbulence interaction correctly. This may be because RANS models do not account for the unsteady motion of the shock wave that is inherent in these interactions. Previous work proposed a shock-unsteadiness correction that significantly improves prediction of turbulent kinetic energy amplification across a normal shock in...

We review the direct numerical simulation (DNS) of turbulent flows. We stress that DNS is a research tool, and not a brute-force solution to the Navier-Stokes equations for engineering problems. The wide range of scales in turbulent flows requires that care be taken in their numerical solution. We discuss related numerical issues such as boundary conditions and spatial and temporal discretizati...

The paper presents a method to perform direct numerical simulations (DNS) of a jet actuator flow inside a turbulent flat plate boundary layer (TBL). A structured finite difference method is used for the simulations. The numerical scheme is adapted to account for the large scale differences both in geometric and fluid dynamic aspect. Analytical mesh transformations have been implemented to resol...

The parametrization of small-scale turbulent fluctuations in convective systems and in the presence of strong stratification is a key issue for many applied problems in oceanography, atmospheric science, and planetology. In the presence of stratification, one needs to cope with bulk turbulent fluctuations and with inversion regions, where temperature, density, or both develop highly nonlinear m...

Recent studies have suggested that in some cases transition can be triggered by some purely nonlinear mechanisms. Here we aim at verifying such an hypothesis, looking for a localized perturbation able to lead a boundary-layer flow to a chaotic state, following a nonlinear route. Nonlinear optimal localized perturbations have been computed by means of an energy optimization which includes the no...

A discontinuous Galerkin (DG) method is formulated, implemented, and tested for simulation of compressible turbulent flows. The method is applied to turbulent channel flow at low Reynolds number, where it is found to successfully predict low-order statistics with fewer degrees of freedom than traditional numerical methods. This reduction is achieved by utilizing local hp-refinement such that th...